US Patent 11183172 Detection of fricatives in speech signals

Detecting fricatives in a noisy speech signal having a clean speech signal and a noise signal, includes bandpass filtering of the noisy speech signal with a first transfer function having a first passband range to provide a first filtered noisy speech signal, and bandpass filtering of the noisy speech signal with a second transfer function having a second passband range, the second passband being different from the first passband to provide a second filtered noisy speech signal. Detecting fricatives further includes applying a maximum operation to the first filtered noisy speech signal and the second filtered noisy speech signal to provide a maximum spectrum that is representative of a frequency range of maximum fricative energy, and deciding, based on the maximum spectrum, whether a fricative is contained in the noisy speech signal. A decision signal is output that is representative of the decision.